[pango/wip/matthiasc/face-lang: 26/26] Add api to get language coverage for faces

[Matthias Clasen <matthiasc src gnome org>]

commit 16ba47a34005f390370f64a108c4b4acce8a9875
Author: Matthias Clasen <mclasen redhat com>
Date:   Sat Dec 23 14:30:45 2017 -0500

    Add api to get language coverage for faces
    
    This is needed to make filtering in the font
    chooser performant.

 pango/fonts.c           |   16 +++++++++
 pango/pango-font.h      |    9 +++++-
 pango/pangofc-fontmap.c |   81 +++++++++++++++++++++++++++++++++++++++++------
 3 files changed, 95 insertions(+), 11 deletions(-)
---
diff --git a/pango/fonts.c b/pango/fonts.c
index d9a07c0..31aa8fb 100644
--- a/pango/fonts.c
+++ b/pango/fonts.c
@@ -2261,3 +2261,19 @@ pango_font_face_list_sizes (PangoFontFace  *face,
       *n_sizes = 0;
     }
 }
+
+void
+pango_font_face_get_languages (PangoFontFace   *face,
+                               PangoLanguage ***languages,
+                               int             *n_languages)
+{
+  g_return_if_fail (PANGO_IS_FONT_FACE (face));
+
+  if (PANGO_FONT_FACE_GET_CLASS (face)->get_languages != NULL)
+    PANGO_FONT_FACE_GET_CLASS (face)->get_languages (face, languages, n_languages);
+  else
+    {
+      *languages = NULL;
+      *n_languages = 0;
+    }
+}
diff --git a/pango/pango-font.h b/pango/pango-font.h
index 4af31a9..9a0b22a 100644
--- a/pango/pango-font.h
+++ b/pango/pango-font.h
@@ -492,6 +492,11 @@ void                  pango_font_face_list_sizes     (PangoFontFace  *face,
 PANGO_AVAILABLE_IN_1_18
 gboolean              pango_font_face_is_synthesized (PangoFontFace  *face) G_GNUC_PURE;
 
+PANGO_AVAILABLE_IN_1_42
+void                  pango_font_face_get_languages  (PangoFontFace   *face,
+                                                      PangoLanguage ***languages,
+                                                      int             *n_languages);
+
 #ifdef PANGO_ENABLE_BACKEND
 
 #define PANGO_FONT_FACE_CLASS(klass)      (G_TYPE_CHECK_CLASS_CAST ((klass), PANGO_TYPE_FONT_FACE, 
PangoFontFaceClass))
@@ -525,10 +530,12 @@ struct _PangoFontFaceClass
   gboolean               (*is_synthesized) (PangoFontFace *face);
 
   /*< private >*/
+  void                   (*get_languages)  (PangoFontFace   *face,
+                                            PangoLanguage ***languages,
+                                            int             *n_languages);
 
   /* Padding for future expansion */
   void (*_pango_reserved3) (void);
-  void (*_pango_reserved4) (void);
 };
 
 #endif /* PANGO_ENABLE_BACKEND */
diff --git a/pango/pangofc-fontmap.c b/pango/pangofc-fontmap.c
index 4e7d74b..6330045 100644
--- a/pango/pangofc-fontmap.c
+++ b/pango/pangofc-fontmap.c
@@ -172,6 +172,8 @@ struct _PangoFcFace
 
   PangoFcFamily *family;
   char *style;
+  PangoLanguage **languages;
+  int n_languages;
 
   guint fake : 1;
 };
@@ -2514,11 +2516,23 @@ pango_fc_face_is_synthesized (PangoFontFace *face)
 }
 
 static void
+pango_fc_face_get_languages (PangoFontFace   *face,
+                             PangoLanguage ***languages,
+                             int             *n_languages)
+{
+  PangoFcFace *fcface = PANGO_FC_FACE (face);
+
+  *languages = fcface->languages;
+  *n_languages = fcface->n_languages;
+}
+
+static void
 pango_fc_face_finalize (GObject *object)
 {
   PangoFcFace *fcface = PANGO_FC_FACE (object);
 
   g_free (fcface->style);
+  g_free (fcface->languages);
 
   G_OBJECT_CLASS (pango_fc_face_parent_class)->finalize (object);
 }
@@ -2539,6 +2553,7 @@ pango_fc_face_class_init (PangoFcFaceClass *class)
   class->get_face_name = pango_fc_face_get_face_name;
   class->list_sizes = pango_fc_face_list_sizes;
   class->is_synthesized = pango_fc_face_is_synthesized;
+  class->get_languages = pango_fc_face_get_languages;
 }
 
 
@@ -2552,17 +2567,47 @@ G_DEFINE_TYPE (PangoFcFamily, pango_fc_family, PANGO_TYPE_FONT_FAMILY);
 static PangoFcFace *
 create_face (PangoFcFamily *fcfamily,
             const char     *style,
-            gboolean       fake)
+            gboolean       fake,
+             PangoLanguage **languages,
+             int             n_languages)
 {
   PangoFcFace *face = g_object_new (PANGO_FC_TYPE_FACE, NULL);
   face->style = g_strdup (style);
   face->family = fcfamily;
   face->fake = fake;
+  face->languages = g_memdup (languages, sizeof (PangoLanguage *) * n_languages);
+  face->n_languages = n_languages;
 
   return face;
 }
 
 static void
+pango_languages_from_langset (FcLangSet       *ls,
+                              PangoLanguage ***languages,
+                              int             *n_languages)
+{
+  GPtrArray *array;
+  FcStrSet *ss;
+  FcStrList *sl;
+  char *s;
+
+  array = g_ptr_array_new ();
+
+  ss = FcLangSetGetLangs (ls);
+  sl = FcStrListCreate (ss);
+  FcStrListFirst (sl);
+
+  while ((s = FcStrListNext (sl)))
+    g_ptr_array_add (array, pango_language_from_string (s));
+
+  FcStrListDone (sl);
+  FcStrSetDestroy (ss);
+
+  *n_languages = array->len;
+  *languages = g_ptr_array_free (array, FALSE);
+}
+
+static void
 pango_fc_family_list_faces (PangoFontFamily  *family,
                            PangoFontFace  ***faces,
                            int              *n_faces)
@@ -2589,14 +2634,14 @@ pango_fc_family_list_faces (PangoFontFamily  *family,
          fcfamily->faces = g_new (PangoFcFace *, fcfamily->n_faces);
 
          i = 0;
-         fcfamily->faces[i++] = create_face (fcfamily, "Regular", TRUE);
-         fcfamily->faces[i++] = create_face (fcfamily, "Bold", TRUE);
-         fcfamily->faces[i++] = create_face (fcfamily, "Italic", TRUE);
-         fcfamily->faces[i++] = create_face (fcfamily, "Bold Italic", TRUE);
+         fcfamily->faces[i++] = create_face (fcfamily, "Regular", TRUE, NULL, 0);
+         fcfamily->faces[i++] = create_face (fcfamily, "Bold", TRUE, NULL, 0);
+         fcfamily->faces[i++] = create_face (fcfamily, "Italic", TRUE, NULL, 0);
+         fcfamily->faces[i++] = create_face (fcfamily, "Bold Italic", TRUE, NULL, 0);
        }
       else
        {
-         FcObjectSet *os = FcObjectSetBuild (FC_STYLE, FC_WEIGHT, FC_SLANT, NULL);
+         FcObjectSet *os = FcObjectSetBuild (FC_STYLE, FC_WEIGHT, FC_SLANT, FC_LANG, NULL);
          FcPattern *pat = FcPatternBuild (NULL,
                                           FC_FAMILY, FcTypeString, fcfamily->family_name,
                                           NULL);
@@ -2624,6 +2669,9 @@ pango_fc_family_list_faces (PangoFontFamily  *family,
            {
              const char *style, *font_style = NULL;
              int weight, slant;
+              FcLangSet *ls;
+              PangoLanguage **languages;
+              int n_languages;
 
              if (FcPatternGetInteger(fontset->fonts[i], FC_WEIGHT, 0, &weight) != FcResultMatch)
                weight = FC_WEIGHT_MEDIUM;
@@ -2634,6 +2682,16 @@ pango_fc_family_list_faces (PangoFontFamily  *family,
              if (FcPatternGetString (fontset->fonts[i], FC_STYLE, 0, (FcChar8 **)(void*)&font_style) != 
FcResultMatch)
                font_style = NULL;
 
+              if (FcPatternGetLangSet (fontset->fonts[i], FC_LANG, 0, &ls) != FcResultMatch)
+                {
+                  languages = NULL;
+                  n_languages = 0;
+                }
+              else
+                {
+                  pango_languages_from_langset (ls, &languages, &n_languages);
+                }
+
              if (weight <= FC_WEIGHT_MEDIUM)
                {
                  if (slant == FC_SLANT_ROMAN)
@@ -2663,19 +2721,22 @@ pango_fc_family_list_faces (PangoFontFamily  *family,
 
              if (!font_style)
                font_style = style;
-             faces[num++] = create_face (fcfamily, font_style, FALSE);
+
+             faces[num++] = create_face (fcfamily, font_style, FALSE, languages, n_languages);
+
+              g_free (languages);
            }
 
          if (has_face[REGULAR])
            {
              if (!has_face[ITALIC])
-               faces[num++] = create_face (fcfamily, "Italic", TRUE);
+               faces[num++] = create_face (fcfamily, "Italic", TRUE, NULL, 0);
              if (!has_face[BOLD])
-               faces[num++] = create_face (fcfamily, "Bold", TRUE);
+               faces[num++] = create_face (fcfamily, "Bold", TRUE, NULL, 0);
 
            }
          if ((has_face[REGULAR] || has_face[ITALIC] || has_face[BOLD]) && !has_face[BOLD_ITALIC])
-           faces[num++] = create_face (fcfamily, "Bold Italic", TRUE);
+           faces[num++] = create_face (fcfamily, "Bold Italic", TRUE, NULL, 0);
 
          faces = g_renew (PangoFcFace *, faces, num);